Change in philosophy headlines Cowboys camp

The Dallas Cowboys head to camp after an offseason of changes on offense and defense, namely the move from the 3-4 to the 4-3 defense and the change in play-callers from head coach Jason Garrett to offensive coordinator/offensive line coach Bill Callahan.

Of course, the biggest story line heading into camp will be the return of quarterback Tony Romo. He missed the entire offseason because of back surgery to remove a cyst that was bothering him. The surgery came just weeks after Romo signed a six-year, $108 million contract extension.

The Cowboys are also giving Romo Peyton Manning-like input in the game-planning and offensive direction so his return to health is a huge priority. He is expected to be full-go at the start of camp. But there's no question all eyes will be on Romo from the outset.

No quarterback has ever reached the Super Bowl after missing an entire offseason. Romo is hoping to be the first. He must hit on all cylinders from the start of the camp.

After setting a dubious team record of most yards yielded in a season, there was a change in defensive coordinators from Rob Ryan to 73-year old Monte Kiffin.

Never mind that they were without five starters for most of the season; the Ryan scheme was unsound and confusing at times. They will get all their healthy players back, but they must make the adjustment to the 4-3 smoothly as there will be no time for a honeymoon with coach Jason Garrett's job on the line if the Cowboys don't make a playoff run. The biggest adjustments player wise are DeMarcus Ware and Anthony Spencer moving from linebacker to defensive end, Jay Ratliff becoming the 3-technique defensive tackle, Bruce Carter going to weak-side linebacker and Sean Lee at middle linebacker. The Cowboys also must find two starters at safety.

Garrett will not call plays for the first time since 2006, handing the reigns over to Callahan, who will call plays in an NFL game for the first time since 2003. Callahan will be up in the booth signaling plays down to quarterbacks coach Wade Wilson. These are things that must be worked through in camp. Callahan is also expected to put a bigger focus on the running game.

The Cowboys drafted center Travis Frederick in the first round to be a walk-in starter and upgrade the offensive line. His fast development in camp is a must as the Cowboys are counting on his size and smarts to make up for deficiencies at guard in Nate Livings and Mackenzy Bernadeau.

On the hot seat: Dez Bryant has gone from a player that held the Cowboys back because of his off-field woes, sideline antics, drops and not knowing the playbook to maybe the guy that can take the team over the top. He is easily the team's best player after a breakout season in 2012 and it's not even close. There was a time when he could be taken out of his game by trash talking or physical play. No more. He finally knows what he is doing and it's showing on the field in his attitude and his performance. The Cowboys are expecting nothing less than a Pro-Bowl season from Bryant and it could put the team over the top.

Cause for concern: Quarterback Tony Romo missed OTAs and minicamp rehabbing from back surgery. No quarterback has ever led his team to the Super Bowl after missing OTAs and minicamp and only one has led his team to the conference title game and that was Brett Favre with the Vikings in 2009. Of course, Favre already had a Super Bowl title and several league MVPs on his resume. Romo has just one playoff win … ever.

Breakthrough star: Linebacker Bruce Carter has star potential written all over him. Sean Lee gets a lot of attention and deservedly so, but the best athlete at the linebacker position as well as fastest player in Carter. There was concern when the Cowboys drafted Carter two years ago that he was more of fit for the 4-3 than the 3-4. He played well in the 3-4 last year before suffering a season-ending injury and now the scheme has come back to his natural position as the weak-side linebacker in the 4-3.

Position battles: Right tackle between Doug Free and Jermey Parnell. The two split the position at the end of last season and will compete for the starting job in training camp. They must not play at last season's level, which was subpar. They both need to improve and somebody needs to step up.

Free safety between Will Allen, Matt Johnson and J.J. Wilcox. This one is wide open. Allen is the experienced veteran brought in for insurance because he is a career backup. Johnson was injured as a rookie last year and remains unknown and unproven. Wilcox is a 2013 third-round pick who has been quite impressive in OTAs and minicamp, but is very raw as he played just one season of safety in college after moving over from receiver.